#!/bin/sh

  # Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>

  # Copyright (C) 2006 Sam Ravnborg <sam@ravnborg.org>

  #

  # Released under the terms of the GNU GPL

  #

  # Generate a cpio packed initramfs. It uses gen_init_cpio to generate

  # the cpio archive, and then compresses it.

  # The script may also be used to generate the inputfile used for gen_init_cpio
  # This script assumes that gen_init_cpio is located in usr/ directory
  
  # error out on errors
  set -e
  
  usage() {
  cat << EOF
  Usage:
  $0 [-o <file>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...

  	-o <file>      Create compressed initramfs file named <file> using
  		       gen_init_cpio and compressor depending on the extension

  	-u <uid>       User ID to map to user ID 0 (root).

  		       <uid> is only meaningful if <cpio_source> is a
  		       directory.  "squash" forces all files to uid 0.

  	-g <gid>       Group ID to map to group ID 0 (root).

  		       <gid> is only meaningful if <cpio_source> is a
  		       directory.  "squash" forces all files to gid 0.

  	<cpio_source>  File list or directory for cpio archive.

  		       If <cpio_source> is a .cpio file it will be used

  		       as direct input to initramfs.
  	-d             Output the default cpio list.
  
  All options except -o and -l may be repeated and are interpreted
  sequentially and immediately.  -u and -g states are preserved across
  <cpio_source> options so an explicit "-u 0 -g 0" is required
  to reset the root/group mapping.
  EOF
  }

  # awk style field access
  # $1 - field number; rest is argument string
  field() {
  	shift $1 ; echo $1
  }

  list_default_initramfs() {
  	# echo usr/kinit/kinit
  	:
  }

  
  default_initramfs() {

  	cat <<-EOF >> ${output}

  		# This is a very simple, default initramfs
  
  		dir /dev 0755 0 0
  		nod /dev/console 0600 0 0 c 5 1
  		dir /root 0700 0 0

  		# file /kinit usr/kinit/kinit 0755 0 0
  		# slink /init kinit 0755 0 0

  	EOF
  }
  
  filetype() {
  	local argv1="$1"
  
  	# symlink test must come before file test
  	if [ -L "${argv1}" ]; then
  		echo "slink"
  	elif [ -f "${argv1}" ]; then
  		echo "file"
  	elif [ -d "${argv1}" ]; then
  		echo "dir"
  	elif [ -b "${argv1}" -o -c "${argv1}" ]; then
  		echo "nod"
  	elif [ -p "${argv1}" ]; then
  		echo "pipe"
  	elif [ -S "${argv1}" ]; then
  		echo "sock"
  	else
  		echo "invalid"
  	fi
  	return 0
  }

  list_print_mtime() {
  	:
  }

  print_mtime() {

  	local my_mtime="0"

  	if [ -e "$1" ]; then
  		my_mtime=$(find "$1" -printf "%T@
  " | sort -r | head -n 1)

  	fi

  
  	echo "# Last modified: ${my_mtime}" >> ${output}
  	echo "" >> ${output}
  }
  
  list_parse() {

  	[ ! -L "$1" ] && echo "$1 \\" || :

  }

  # for each file print a line in following format
  # <filetype> <name> <path to file> <octal mode> <uid> <gid>
  # for links, devices etc the format differs. See gen_init_cpio for details

  parse() {
  	local location="$1"

  	local name="/${location#${srcdir}}"

  	# change '//' into '/'

  	name=$(echo "$name" | sed -e 's://*:/:g')

  	local mode="$2"
  	local uid="$3"
  	local gid="$4"
  	local ftype=$(filetype "${location}")
  	# remap uid/gid to 0 if necessary

  	[ "$root_uid" = "squash" ] && uid=0 || [ "$uid" -eq "$root_uid" ] && uid=0
  	[ "$root_gid" = "squash" ] && gid=0 || [ "$gid" -eq "$root_gid" ] && gid=0

  	local str="${mode} ${uid} ${gid}"

  	[ "${ftype}" = "invalid" ] && return 0
  	[ "${location}" = "${srcdir}" ] && return 0

  
  	case "${ftype}" in
  		"file")
  			str="${ftype} ${name} ${location} ${str}"
  			;;
  		"nod")

  			local dev=`LC_ALL=C ls -l "${location}"`
  			local maj=`field 5 ${dev}`
  			local min=`field 6 ${dev}`
  			maj=${maj%,}
  
  			[ -b "${location}" ] && dev="b" || dev="c"
  
  			str="${ftype} ${name} ${str} ${dev} ${maj} ${min}"

  			;;
  		"slink")

  			local target=`readlink "${location}"`

  			str="${ftype} ${name} ${target} ${str}"
  			;;
  		*)
  			str="${ftype} ${name} ${str}"
  			;;
  	esac

  	echo "${str}" >> ${output}

  
  	return 0
  }

  unknown_option() {
  	printf "ERROR: unknown option \"$arg\"
  " >&2
  	printf "If the filename validly begins with '-', " >&2
  	printf "then it must be prefixed
  " >&2
  	printf "by './' so that it won't be interpreted as an option." >&2
  	printf "
  " >&2
  	usage >&2
  	exit 1
  }
  
  list_header() {

  	:

  }
  
  header() {
  	printf "
  #####################
  # $1
  " >> ${output}
  }
  
  # process one directory (incl sub-directories)
  dir_filelist() {
  	${dep_list}header "$1"
  
  	srcdir=$(echo "$1" | sed -e 's://*:/:g')

  	dirlist=$(find "${srcdir}" -printf "%p %m %U %G
  ")

  
  	# If $dirlist is only one line, then the directory is empty
  	if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
  		${dep_list}print_mtime "$1"
  
  		echo "${dirlist}" | \
  		while read x; do
  			${dep_list}parse ${x}
  		done
  	fi

  }

  # if only one file is specified and it is .cpio file then use it direct as fs
  # if a directory is specified then add all files in given direcotry to fs
  # if a regular file is specified assume it is in gen_initramfs format
  input_file() {
  	source="$1"
  	if [ -f "$1" ]; then
  		${dep_list}header "$1"

  		is_cpio="$(echo "$1" | sed 's/^.*\.cpio\(\..*\)\?/cpio/')"

  		if [ $2 -eq 0 -a ${is_cpio} = "cpio" ]; then

  			cpio_file=$1

  			echo "$1" | grep -q '^.*\.cpio\..*' && is_cpio_compressed="compressed"

  			[ ! -z ${dep_list} ] && echo "$1"
  			return 0
  		fi
  		if [ -z ${dep_list} ]; then
  			print_mtime "$1" >> ${output}
  			cat "$1"         >> ${output}

  		else

  		        echo "$1 \\"

  			cat "$1" | while read type dir file perm ; do

  				if [ "$type" = "file" ]; then

  					echo "$file \\";
  				fi
  			done

  		fi

  	elif [ -d "$1" ]; then
  		dir_filelist "$1"

  	else

  		echo "  ${prog}: Cannot open '$1'" >&2

  		exit 1
  	fi
  }

  prog=$0

  root_uid=0
  root_gid=0

  dep_list=
  cpio_file=
  cpio_list=
  output="/dev/stdout"
  output_file=""

  is_cpio_compressed=

  compr="gzip -n -9 -f"

  arg="$1"
  case "$arg" in
  	"-l")	# files included in initramfs - used by kbuild
  		dep_list="list_"

  		echo "deps_initramfs := $0 \\"

  		shift
  		;;

  	"-o")	# generate compressed cpio image named $1

  		shift
  		output_file="$1"
  		cpio_list="$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)"
  		output=${cpio_list}

  		echo "$output_file" | grep -q "\.gz$" && compr="gzip -n -9 -f"

  		echo "$output_file" | grep -q "\.bz2$" && compr="bzip2 -9 -f"
  		echo "$output_file" | grep -q "\.lzma$" && compr="lzma -9 -f"

  		echo "$output_file" | grep -q "\.xz$" && \
  				compr="xz --check=crc32 --lzma2=dict=1MiB"

  		echo "$output_file" | grep -q "\.lzo$" && compr="lzop -9 -f"

  		echo "$output_file" | grep -q "\.cpio$" && compr="cat"

  		shift
  		;;
  esac

  while [ $# -gt 0 ]; do
  	arg="$1"
  	shift
  	case "$arg" in

  		"-u")	# map $1 to uid=0 (root)

  			root_uid="$1"
  			shift
  			;;

  		"-g")	# map $1 to gid=0 (root)

  			root_gid="$1"
  			shift
  			;;

  		"-d")	# display default initramfs list

  			default_list="$arg"

  			${dep_list}default_initramfs

  			;;
  		"-h")
  			usage
  			exit 0
  			;;
  		*)
  			case "$arg" in
  				"-"*)

  					unknown_option

  					;;

  				*)	# input file/dir - process it
  					input_file "$arg" "$#"

  					;;
  			esac
  			;;
  	esac
  done

  # If output_file is set we will generate cpio archive and compress it

  # we are careful to delete tmp files

  if [ ! -z ${output_file} ]; then
  	if [ -z ${cpio_file} ]; then

  		timestamp=
  		if test -n "$KBUILD_BUILD_TIMESTAMP"; then
  			timestamp="$(date -d"$KBUILD_BUILD_TIMESTAMP" +%s || :)"
  			if test -n "$timestamp"; then
  				timestamp="-t $timestamp"
  			fi
  		fi

  		cpio_tfile="$(mktemp ${TMPDIR:-/tmp}/cpiofile.XXXXXX)"

  		usr/gen_init_cpio $timestamp ${cpio_list} > ${cpio_tfile}

  	else
  		cpio_tfile=${cpio_file}
  	fi
  	rm ${cpio_list}

  	if [ "${is_cpio_compressed}" = "compressed" ]; then
  		cat ${cpio_tfile} > ${output_file}
  	else

  		(cat ${cpio_tfile} | ${compr}  - > ${output_file}) \
  		|| (rm -f ${output_file} ; false)

  	fi

  	[ -z ${cpio_file} ] && rm ${cpio_tfile}
  fi

  exit 0